php—ArrayAccess介面

提供像訪問數組一樣訪問對象的能力的介面。

介面摘要

ArrayAccess {    /* 方法 */    abstract public boolean offsetExists ( mixed $offset )    abstract public mixed offsetGet ( mixed $offset )    abstract public void offsetSet ( mixed $offset , mixed $value )    abstract public void offsetUnset ( mixed $offset )}

Example #1 使用範例

<?php    class obj implements ArrayAccess {        private $container = array();        public function __construct() {            $this->container = array(                "one" => 1,                "two" => 2,                "three" => 3,            );        }        public function offsetSet($offset, $value) {            if (is_null($offset)) {                $this->container[] = $value;            } else {                $this->container[$offset] = $value;            }        }        public function offsetExists($offset) {            return isset($this->container[$offset]);        }        public function offsetUnset($offset) {            unset($this->container[$offset]);        }        public function offsetGet($offset) {            return isset($this->container[$offset]) ? $this->container[$offset] : null;        }    }    $obj = new obj;    var_dump(isset($obj["two"]));    var_dump($obj["two"]);    unset($obj["two"]);    var_dump(isset($obj["two"]));    $obj["two"] = "A value";    var_dump($obj["two"]);    $obj[] = 'Append 1';    $obj[] = 'Append 2';    $obj[] = 'Append 3';    print_r($obj);?>

以上常式的輸出類似於：

bool(true)int(2)bool(false)string(7) "A value"obj Object(    [container:obj:private] => Array        (            [one] => 1            [three] => 3            [two] => A value            [0] => Append 1            [1] => Append 2            [2] => Append 3        ))

方法列表

ArrayAccess::offsetExists — 檢查一個位移位置是否存在

ArrayAccess::offsetGet — 擷取一個位移位置的值

ArrayAccess::offsetSet — 設定一個位移位置的值

ArrayAccess::offsetUnset — 複位一個位移位置的值

